Reports of a newly operational nuclear enrichment facility in North Korea highlight the regime's defiance of U.S. policy and UN sanctions as well as China's increasing closeness with North Korea, says CFR's Scott Snyder.

Venezuela's stepped-up efforts to develop nuclear power and tighten its bonds with Iran require a firm but deft diplomatic response from the Obama administration, write CFR's Joel Hirst and Jonathan Pearl.

Iran's fueling of the Bushehr reactor is a reminder of ongoing concerns about the country's nuclear intentions. Negotiations with Iran on a broad set of issues, though unlikely, might be the best path, says CFR's Emma Belcher.

For decades, Israel has maintained an "opaque" nuclear posture -- neither confirming nor denying that it possesses nuclear weapons. The time has come for Israel to reconsider the policy of nuclear ambiguity.

Though a new IAEA report adds to concerns about Iran's nuclear program and U.S. opposition to the program is warranted, there's no clear proof that the country is pursuing weapons or would act belligerently if it succeeded, says CFR's Matthew Fuhrmann.

CFR's Stephen Sestanovich says Russian President Dmitry Medvedev's meetings in Silicon Valley represent the most interesting development of his U.S. trip, which culminates with a Washington summit where a host of issues will be discussed, including the new START treaty.